P0340 on Chevrolet
Camshaft Position Sensor Circuit Malfunction
P0340 on Chevrolet vehicles indicates camshaft position sensor circuit malfunction. Au7o has documented this code across 1 Chevrolet model — most commonly on Corvette. This code means the engine computer lost or received an erratic signal from the camshaft position sensor. That sensor tells the computer the exact position and speed of the camshaft, which it uses together with the crankshaft sensor to time fuel injection and spark precisely. When the camshaft signal is missing, intermittent, or out of range, the computer sets P0340. Symptoms often include hard starting, stalling, rough running, or a no-start because the engine can't time itself correctly. Typical repair costs on Chevrolet range from $800 to $2,000, depending on the specific model and root cause.
Common Causes of P0340
- •Failed camshaft position sensor
- •Corroded or loose sensor connector
- •Damaged or shorted sensor wiring
- •Bad reluctor/tone ring on the camshaft
- •Loose timing chain/belt or jumped timing
- •Metal debris or oil contamination on the sensor tip
- •Poor sensor power or ground supply
- •Faulty PCM/ECM (rare)
P0340 on Chevrolet by Model
Chevrolet Corvette(2 issues)
- Opti-Spark (Optispark) Distributor Failure on LT1/LT4 Engines1992-1996
The LT1 (and 1996 LT4) uses a front-of-engine 'Opti-Spark' optical distributor mounted low behind the water pump, driven off the camshaft. It is highly vulnerable to moisture, heat, and ozone. The 1992-1993 units were completely unvented and are notorious for internal condensation and corrosion of the optical sensor disc. The leading real-world cause of failure is a leaking water pump directly above it dripping coolant onto/into the unit, but ordinary humidity and age also kill them. It is one of the single most defining reliability weak points of the 1992-1996 C4.
- Opti-Spark Optical Distributor Failure (LT1)1992-1996
The 1992-1996 LT1 uses the Opti-Spark optical distributor mounted low on the front of the engine, directly behind the water pump. Undersized factory vent/drain holes trap condensation, and any coolant seepage from the water pump weep hole or oil from the front crank seal corrodes the optical sensor and internal contacts. When the high-resolution signal degrades, the engine misfires, backfires, and can stall without warning and refuse to restart, often stranding the owner. The 1995-1996 vented design lasts longer but still fails with age.
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View P0340 across all makes →Frequently Asked Questions
What does P0340 mean on Chevrolet?▼
P0340 stands for "Camshaft Position Sensor Circuit Malfunction." This code means the engine computer lost or received an erratic signal from the camshaft position sensor. That sensor tells the computer the exact position and speed of the camshaft, which it uses together with the crankshaft sensor to time fuel injection and spark precisely. When the camshaft signal is missing, intermittent, or out of range, the computer sets P0340. Symptoms often include hard starting, stalling, rough running, or a no-start because the engine can't time itself correctly. On Chevrolet specifically, this code is documented across 1 model.
What causes P0340 on Chevrolet vehicles?▼
Common causes on Chevrolet: Failed camshaft position sensor, Corroded or loose sensor connector, Damaged or shorted sensor wiring, Bad reluctor/tone ring on the camshaft, Loose timing chain/belt or jumped timing. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P0340 on a Chevrolet?▼
Repair costs on Chevrolet range from $800 to $2,000, depending on the specific model and root cause.
Which Chevrolet models have P0340 documented?▼
Au7o has documented P0340 on 1 Chevrolet model: Corvette.